


working hypothesis

by Sixthlight



Category: Rivers of London - Ben Aaronovitch
Genre: Future Fic, Inspired By Tumblr, M/M, cameo appearances by the rest of the cast
Language: English
Status: Completed
Published: 2016-06-03
Updated: 2016-06-03
Packaged: 2018-07-11 23:22:55
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,396
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7074982
Author URL: https://archiveofourown.org/users/Sixthlight/pseuds/Sixthlight
Summary: <blockquote class="userstuff">
              <p>"Only because I'm going to go mad if you keep not talking about this for another half-hour," said Jaget, "have you considered the possibility that you're jealous?"</p>
            </blockquote>





	working hypothesis

**Author's Note:**

  * For [stardust_rain](https://archiveofourown.org/users/stardust_rain/gifts).



> Inspired by [this story](http://empyrrhic.tumblr.com/post/145285441515/surprisebitch-heres-the-link-to-the-full) that's been doing the rounds on Tumblr.

 

 

It started one Tuesday evening in February when I walked into the foyer at the Folly after dinner and saw Nightingale in his oyster-white Burberry coat, wrapping a steel-grey scarf around his neck that brought out his eyes. Not that he probably paid any attention to stuff like that; Nightingale's clothing appeared to be entirely a product of habit and inculcation.

"Please tell me it's not a case," I said, because I'd been up until three am this morning for a murder that hadn't even been anything to do with us in the end, and my plans for the evening mostly involved my bed.

"Not a case," Nightingale said obligingly. "I'm just going out. You can still call me if something comes up, though."

"Going...out?" I echoed.

"To a jazz concert," he said. "Daniel Hossack told me about it."

"Right." My mind was blanking, like a record that had skipped; I knew Nightingale had met the Irregulars, and I knew Nightingale liked jazz, so why was this so weird? "Well...have fun?"

"I think I will," Nightingale said with a small smile, and I excused myself from having to think about it any further by going to bed. Luckily for me _and_ Nightingale, the phone didn't ring.

* 

Two weeks later, Nightingale popped into the tech cave to say that he was going out for dinner.

"With Abdul?" I asked, not really paying attention. It was the most likely thing; he and Nightingale went out for dinner and rugby at a pub now and again, and I had a standing invitation to come along if I felt like it. I figured that was why Nightingale was telling me now, although I was already preparing to say no - I was supposed to be going out with Bev and some friends. I hadn't seen a lot of her lately - not as little as just after we'd called it off, but we'd both been busy - and I was looking forward to catching up.

"No," Nightingale said, and that surprised me enough I turned away from the computer to look at him; he didn't _have_ that many friends. "Someone I met at the concert; he's a colleague of Daniel's."

"Like...going out, going out?" I said before I could think better of it.

"Well, I hope so," said Nightingale, and my brain skipped again. That was so totally unexpected I don't even know what I said next, before he left; something about hoping he had a nice time. I think.

Nightingale got home about eleven, an hour or so after me. I'd gone back to the tech cave when I got back to check something I'd seen in HOLMES earlier in the day. Bev had said something that had made me think.

He was by himself. Not that I was checking. I just noticed. 

*

"This is definitely...new," I said to Beverley. We were drinking coffee and walking along the riverbank; this would have been a lot more pleasant if it hadn't been barely spring. Beverley looked perfectly comfortable in her wetsuit, but that's goddesses for you. "When I first showed up he didn't really go out at all, not that I noticed, and now apparently he's _going out_ , and it's - he's nearly a hundred and twenty, I think I thought he’d gotten it out of his system back in the thirties."

"My brother-in-law was, like, two hundred and something when he and Effra got together," Bev pointed out. "You need to stop thinking so - normal."

"Look, I'm not saying he _can't_ , I'm just saying it's an adjustment. In my thinking."

Beverley frowned, opened her mouth, then closed it.

"What?"

"You know what, never mind," she said. "Enough about the Nightingale's love-life." Hearing her phrase it that way made my stomach do a weird flip, but she went on. "How'd that experiment with the staff and the rats turn out?"

I want to say I realised she was distracting me and nobly decided to let it pass, but the truth is I was really excited about that experiment and I didn't even notice until two hours later. 

*

"You don't understand," I told Sahra. "You don't have to live with your boss, her personal life isn't in your face."

"I had dinner with her and the wife last week," said Sahra. "It was a really nice evening, actually.  I said hi to the chickens. And you've been living with Nightingale for years and years, why's it a problem now?"

"I don't _live with him_ , it's a really big building, we - he's never done this before, as far as I knew until recently he didn't even have a - he wasn't interested in...dating."

"Is it 'cos he's gay, that’s what bothers you?" Sahra asked, giving me the side-eye.

"What? No!"

"Hmph." Sahra stared out the window of the Jag for a few seconds as I turned onto the roundabout. "Have you actually met the boyfriend yet?"

"I don't think they're - I think they only went out twice," I said quickly. "So. No. Which is fine, because it's not my business, that's what you're going to say, right?"

"Hmmm," said Sahra again, and then some idiot in an Audi did a very illegal u-turn so we made the mutual and elective decision to do some on-the-spot policing. We were on the way back from an interview and weren't in a rush, so it was karma in action, really.

* 

"Anybody falling over drunk yet?" I asked Abigail. We were policing the Spring Court. I say "we", but Abigail was still a probationer even if she was champing at the bit to get done with it and officially join the Folly - we'd just got her on loan for this.

"Nah, nothing serious going on," Abigail said. "Although I did see Ash hitting on Nightingale in the music tent, that was pretty funny."

"Huh," I said, suddenly very aware of the need to keep my face straight. "Anything else?"

Abigail hesitated, looking worried.

"Well, what is it?"

"Do you....want to go and walk around for a bit?"

"I'm good here," I said, nodding at the stall. "Privileges of rank. Keep walking, constable."

"Are you _sure_?" she persisted. "You could...go and check in with Nightingale."

"Sounds like he might not want to be bothered." I was trying _very_ hard not to think about that; I'd seen enough of Ash's flirting technique up close, if not aimed at me, that slightly disastrous summer I'd spent babysitting him. And Nightingale - yeah, definitely best not thought about.

"Fine, okay," said Abigail, in a magnificent display of the kind of insubordination I was going to have to put up with for the next however many years. "I'll keep walking."

I wondered what had made her so twitchy.

* 

"It's just that what if he brought someone back to the Folly?" I said. "That would be weird. I bet Molly would get upset. Change of routine and everything. She practically had him to herself for seventy years."

"You bring people back to the Folly all the time," said Lesley, from around the corner of a very nice Victorian wrought iron fence. It was currently less nice than it had been, because my aim isn't good when I'm surprised.

"I do not! Not like that. I bring people to the Folly for _work_. Or friends. Not the same thing."

Admittedly this wasn't for lack of trying, but there was that issue with the wards, sorry, "protections", and my hit rate with non-supernatural women was depressing low. What else was I going to do, hook up with someone in the tech cave? It got way too much use these days for that, between Nightingale having email and Molly’s other life on the internet. And neither the chaise longue or the couch was that comfortable, I knew from experience. And - anyway, I didn't.

"Okay, but you would if you ever dated anybody normal," Lesley said ruthlessly as she ducked - or so I presume, I was working off the sound of her voice.

"Look, this isn't about me." I hit the ground and rolled up again - I'd be a lot more annoyed about my jacket if Molly wasn't so good at getting mud and other, less identifiable stains out. "It's about Nightingale and how weird it is that he's...seeing people. It's weird, right? You agree it's weird."

"Did you come here to complain about him or arrest me?" demanded Lesley.

"Yes," I said, because I'm too honest for my own good.

I got a fireball in response, but it was moving pretty slowly and it wasn't any effort to bat it away, so I don't think she was really that annoyed.

I did feel a bit bad about the fence, though. 

*

"I heard there's trouble at the Folly," said Jaget. We were at his place drinking Kingfisher and playing Mario Kart.

"From who?"

"People," he said evasively, which probably meant Bev. Or Sahra. Or even Abigail. I didn't think he was in touch with Lesley. Although, frankly, you never knew. "Heard your boss is dating and you're acting weird about it."

"He's not," I said, because he wasn't; whoever jazz concert guy had been, Nightingale hadn't been out with him in weeks and the Ash thing had definitely been Abigail's fevered imagination. I mean, I hadn't asked, because that would have gotten way too personal, but I was pretty sure he was back to his usual single state. It was good. Back to normal.

"Oooookay," said Jaget. "It bothers you that much?"

"Of course not, why would it." I paused to navigate a particularly tricky turn. "But apparently people are getting the idea that it bothers me, which makes me think I might be making _him_ think it bothers me, and that’s a problem. I don't want to - it doesn't bother me, it really doesn’t." The sentence that wanted to trip off my tongue was "I have lots of gay friends", but any conversation that starts with that sort of sentence is one that's about to go rapidly downhill in a way unflattering to the speaker, so I prudently kept my mouth shut.

"You could tell him it doesn't bother you," suggested Jaget.

"Definitely protesting too much."

"Yeah, but you two are...friends, right? Pretty much."

"This isn't really the kind of thing we talk about."

"I thought he set you up with Bev, back when?"

I made a face. "That sounds - yeah, he got her to come help me in Herefordshire, but that was a work thing, not - he wasn't _setting us up_." Much. Probably. Maybe you could say facilitating. I hadn’t asked what he thought he was doing.

"But obviously he knew you liked her."

"I told you, this isn't the kind of thing we talk about," I said again, and I remembered when I'd broken up with Bev, which hadn't been traumatic, or anything, just - anticlimactic. Nightingale had taken one look at me when I'd gotten back to the Folly and, instead of asking if I was feeling alright, announced that he really needed me to find a stack of references in the library, preferably yesterday. It was the kind of thing I liked about him, as a friend. Boss. Person I lived with. Lived in the same building as. Whatever. "And I don't want to talk about it, because it's not my business, in fact it's probably better if he's getting out, because he was stuck in the Folly with just Molly for company for decades as far as I can tell, and -"

"Only because I'm going to go mad if you keep not talking about this for another half-hour," said Jaget, "have you considered the possibility that you're jealous?"

"Because my boss is having better luck pulling right now than I am?"

Jaget sighed. "No. Because _you_ want to date him."

On the screen, I skidded on a banana peel and did a neat flip right off the Rainbow Road and into video-game oblivion.

"What," I said.

"You heard me the first time."

"What," I said again. "No. I - no. That's - no."

"Uh-huh," said Jaget, as he crossed the finish line. I'd reappeared at the start line, but I didn't bother starting again; the controller felt suddenly heavy in my hands. I put it down and took a swig of beer instead.

"I just don't understand what would make you suggest that," I said.

"But you're thinking about it."

"I'm thinking about how we should go best of five on this." I gestured at the screen.

"Tell Bev I tried," said Jaget, sounding resigned.

I didn't think about what he meant by that, either. 

*

"Peter," said Nightingale, poking his head into the lab.

"Going out again tonight?" I asked, keeping my eyes on the werelight I was running off a five-quid calculator. I was trying to get really good numbers for the lumen output/time/energy ratio, but it was tricky when I couldn't use a really accurate stopwatch.

"No," he said, sounding amused. "I came to see whether you were planning on eating dinner tonight."

Shit. I'd totally lost track of the time. "How much have I annoyed Molly?"

"Not at all, if you show up in the next five minutes. You're not quite late yet."

The werelight reddened and then winked out; I clicked the old mechanical stopwatch, and made sure to record the time before I said anything else. "Thanks for coming and finding me, then." It wasn't like there were serious consequences for being later for dinner in this establishment, aside from having your plate set down with extra force or your food cold, but I was on thin ice with Molly right now over an unfortunate incident with a spell involving _aqua_ , so better not to make her any grumpier.

"I don't mean to pry," Nightingale began carefully as we headed for the dining room, Toby at our heels, "but has something been bothering you lately?"

"Oh, not you too." I could feel my ears heating up; this was exactly what I hadn't wanted to happen. "It's not - it's nothing. It's fine. Everything is fine."

Nightingale gave me a look that said _it's not but I can see it's going to be more trouble than it's worth to get you to talk about it right now_ , and I smiled a bit sheepishly to let him know it wasn't that bad, and then I wondered how much I'd been lying to Jaget when I'd said _we don't talk about that_ , because the actual talking was more optional than I realised.

I managed to keep my mouth shut - or at least talk about less difficult things - until after dinner, when I was trying to decide whether to go back to the lab or take the evening off, go watch some telly or something. I hesitated at the point where I'd have to turn either towards the back door or back into the Folly.

"Experiments to finish?" asked Nightingale, coming up behind me.

"It was bothering me that you were going out with - people," I said, and then wanted very fervently to die.

"With men," said Nightingale, very neutrally, and I fixed very hard on the opposite wall because if I'd had to look at him - I couldn't look at him.

" _No_ ," I said, "no, that - why do people keep _asking_ that, no, I -"

A whole lot of ways to finish that sentence flashed through my mind, like _I don't like it when things change and I don't know why_ , and _it turns out your attention is a lot more important to me than I realised_ , and _I don't want to have to think about you kissing people or anything else so maybe could you just not do that_ , and _if I knew what I was upset about this I could stop being upset about it_.

"I have a working hypothesis, but it's not very probable," I said finally. I didn't blame Jaget, even though he deserved it, because I wasn't about to let Nightingale think this was something I'd spent that much time talking about.

"I'm at a bit of a loss as to what it could be," Nightingale said, and I risked looking at him; he looked worried and a little bit sad, and it felt a bit like being punched in the stomach, and oh. Shit.

"That," I said, with a feeling a bit like the building shivering under me at Skygarden, "I don't have a problem with you going out with people in the, the abstract, so much as in the concrete of you going out with people. Who aren't. Uh. Me."

"Oh," he said, hesitated, licked his lips like he was about to say something else, and I realised I was staring a bit and mentally upgraded _working hypothesis_ to _probable cause_.

"Look, I'm sorry," I tried, "that wasn't - appropriate, and I'm just going to -"

"I'm not in the habit of asking questions I'm not prepared to hear the answers to." He smiled faintly, and something fizzed up my spine. He hadn't really asked a question, of course. “How’s the hypothesis coming along?”

I realised, with a click of things falling into place so strong it was almost audible, that of course Nightingale wasn’t going to – Nightingale _couldn’t_ –

“I think the evidence is in its favour,” I said, and kissed him.

It wasn’t weird. It was very not weird.

I'm not going to tell you what happened next. Suffice it to say we tested my hypothesis experimentally and very thoroughly.

The scientific method really is a wonderful thing.

 

*

"Pax," Lesley said, appearing next to me at the goblin market. This week it was in a cavernous old warehouse in the East End that probably should have been demolished a few decades back. "I'm not here to fight."

"I've already been kicked out of the market once this year," I said. "And so have you. What do you want, then?"

"I'm here to get a drink and have a chat," she said. "You can do what you like." So I exercised my discretion and sat down with her for a drink. That's community policing for you.

Lesley insisted on buying my beer, which I would have found more suspicious if Zach hadn't been bartending; he gave me a nod. It wasn't that I trusted him to take my side over Lesley's, it was that putting something in my drink wasn't the kind of thing he'd take her side over.

"I hear you sorted out your Nightingale problem," said Lesley as soon as I went to take a sip, and smirked when it made me splutter. I didn't like her smirk. It was as unlike her old face as it was possible for two faces to be. It was someone else's smirk. It was someone else's face, but that - that was the sort of thing we _really_ never talked about.

"Shut up," I told her.

"It's okay," she said. "I won twenty quid off Bev, that's why I'm buying. She said you'd never get your act together enough to even figure out what was making you sulk around the place like someone had died, much less ask him out. And she'd know, you gave her enough of a runaround back when."

"You won - don't tell me," I said, because I didn't want to know how deep the conspiracy went. But I definitely blamed Jaget. "I was not _sulking_.”

"It was tragic, you were reaching new heights of obliviousness even for you," she said. "Don't tell me anything, _I_ still think it's weird. What are you at the market for, anyway?"

"Just keeping in touch with the community," I said with a bland smile, "what about you?", and we prevaricated at each other for a while, but not more than normal, and I think most of what she said was true. Most of what I said was, too, within limit and reason. With Lesley, these days, I took what I could get.

"Can't stay too long," I said finally, putting down my empty bottle.

"More community policing to do?" she asked, slinging an arm over the back of the chair next to her. "I won't keep you, then.

"Got to get on with it, yep," I said, standing up. "Places to be after this.”

Lesley raised an eyebrow.

I grinned. "I've got a date."

Her expression then was totally Lesley May - and totally worth it.

 

**Works inspired by this one:**

  * [[Podfic of] working hypothesis](https://archiveofourown.org/works/13101483) by [knight_tracer](https://archiveofourown.org/users/knight_tracer/pseuds/knight_tracer)
  * [[Podfic] Working Hypothesis](https://archiveofourown.org/works/13270371) by [greedy_dancer](https://archiveofourown.org/users/greedy_dancer/pseuds/greedy_dancer)




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